Electrical floor fittings which are insertable through a floor opening for providing both electrical power service and telephone service between opposite surfaces of the floor are commonly referred to by those working in the art as "poke-thru" floor fittings because they are vertically insertable through the opening. Such fittings typically mount a floor box head at one end thereof which rests on the upper floor surface and an electrical junction box at the opposite end thereof adjacent the lower surface of the floor. Electrical conductors appropriate for each type of service pass through the fitting and hard wire or plug-in connections are made to these conductors at the floor and junction boxes, respectively. The fittings are attached fixedly to the floor, either by clamping devices attached to the fittings which engage the under floor surface or by devices which can be displaced outwardly to grip the wall defining the floor opening.
In order to facilitate the installation of these fittings in floor openings from the upper floor surface, the junction box of the fitting may be made sufficiently narrow to pass vertically down through the opening. A prior art junction box of this particular type is disclosed generally in U.S. Pat. No. 4,323,724 and an enlarged, full sectional side view of a typical embodiment of this prior art type of junction box and an adjoining fitting tube or conduit is illustrated in FIG. 1 of the instant application to facilitate an understanding of the construction of this type of junction box.
With reference to FIG. 1 hereof, the prior art junction box 10 is made of a fire-resistant metal, such as steel, and is fixedly attached by, for example, welding to the lower end of a vertically-disposed, hollow metal tube or conduit 11. A longitudinal divider plate 12 partitions the tube 11 longitudinally into respective electrical power and communications service compartments.
The junction box 10 is elongated and narrow enough to pass freely through the floor opening through which the telephone and power conductors must pass. A portion of the tube 11 which is in the floor opening may mount a horizontal plate or other means which supports fire and smoke barriers for preventing the passage of fire and smoke through the fixture and the floor opening. The fire barriers are typically composed of a stack of horizontally disposed intumescent discs or plates which expand horizontally and vertically when subjected to high temperatures, as encountered in a fire situation, to block off open spaces between the fitting and the internal wall of the opening.
The junction box 10 may be of overall rectangular shape for facilitating its endwise insertion through the floor opening from the upper floor surface. A flat front cover plate 14 on the box 10 is fixedly attached to the conduit 11 and has a generally L cross-sectional shape. A rear cover plate 16, which is also typically flat, is removably attached at its lower end to the rearwardly extending leg 14A of the front cover 14 by a machine screw 18. At its upper end, the plate 16 is removably attached to the tube 11 by a machine screw 19. A divider plate 21, also composed of a fire-resistant metal such as steel, partitions the junction box 10 into a telephone service compartment 30 and an electrical power service compartment 31; the lower end of the divider plate 21 being removably attached to the inside surface of the front cover 14 by a machine screw 22. The upper end of the plate 21 abuts one side of a divider plate 12 which passes upwardly through the tube 11 so as to complete the partitioning of the conduit and junction box longitudinally into two partitioned service compartments which respectively communicate with the telephone service compartment 30 and the power service compartment 31 in the junction box 10.
The electrical wires and associated connectors required for each type of service are conventional and are ommitted for purposes of clarity.
A conventional cylindrical knock-out plug 32 is located slightly rearwardly of the front face of the cover 14 and is circumscribed by a circular, partially cut through opening 32A through which the telephone wires can pass once the plug 32 is knocked rearwardly into the compartment 30 by the telephone installer. Frontal access to the telephone service compartment 30 is therefore only available through the opening 32A. Access to the power service compartment 31 can be gained by removing the rear cover plate 16 after unscrewing and removing both mounting screws 18 and 19. Conventional cylindrical knock-out plugs 33 are formed in the plate 16 and cover partially cut-through openings through which the cord end containing the electrical power wires may be inserted once one of the plugs 33 is knocked out.
To hard-wire the fitting of FIG. 1, commencing with the power conductors, typically one of the knock-out plugs 33 is first punched into the power service compartment 31 by an electrician who thereafter detaches the back cover plate 16 to gain access to the power service compartment 31 by removing mounting screws 18 and 19. One end of the insulated electrical cord containing the power conductors is then inserted through the knock-out opening in the plate 16 into the compartment 31 where electrical connections are made to the lower terminal ends of power wires which hang loosely in the tube 11. The upper ends of such conductors are also connected to appropriate terminals on wiring devices, such as receptacles, mounted in the fitting head (not shown) on the upper floor surface. Once connections to the power conductors are made, as by wire nuts, the back plate 16 is reattached to the front cover 14 by reinserting and turning the screws 18 and 19.
Assuming that telephone service installation is also desired, typically, a telephone service installer will knock the slightly rearwardly positioned plug 32 into the compartment 30 to open up the front cover plate for the insertion of a telephone cord into the compartment 30 through the opening 32A left by the plug 32. The plug 32 should be removed from the telephone compartment because it is in a position to interfere with the making of the telephone connections. Inasmuch as the telephone conduit opening 32A is too small to permit its easy withdrawal through that same opening, the telephone installer will usually resort to removing the back cover 16 by removing the screws 18 and 19 and then the divider plate 21, which normally blocks rearward access to the telephone compartment 30 by unscrewing the screw 22. However, if the telephone installer follows the electrician in wiring sequence, as is typically the case in these types of hybrid communication/power service installations, the power service compartment 31 will already be occupied by the power cord. Thus, the telephone installer is faced with a relatively difficult and possibly even dangerous job of having to manipulate the divider plate 21 and the loose telephone knock-out plug 32 past the connected power conductors in the compartment 31. This needs to be done carefully so as not to disrupt any of the electrical connections previously made in the power service compartment 31 and hence, the whole procedure is time-consuming.
To summarize, with this prior art junction box, if access to the telephone compartment 30 is desired through other than the relatively small opening 32A in the front cover, it must be made through the power service compartment. Moreover, this arrangement requires the telephone installer remove oppositely positioned covers on the box and access oppositely facing compartments which is time-consuming and inefficient.